Silver halide emulsion containing a polymeric polyamine as an acid dye mordant



silver halide emulsion layers.

United States Patent SILVER HALE EMULSIUN CONTAINING A POLYMERICPOLYAMTNE AS AN ACID DYE MORDANT Russell Houston Gray, MiddletownTownship, Monmouth County, N. .l., assignor to E. I. du Pont de Nemoursand Company, Wilmington, Del., a corporation of Delaware No Drawing.Application September 10, 1953, Serial No. 379,467

16 Claims. (Cl. 95-7) This invention relates to photography and moreparticularly to photographic materials containing mordanting agents.Still more particularly, it relates to photographic elements having atleast one water-permeable colloid silver halide emulsion containing apolymeric polyamine having at least one unsubstituted hydrogen atom onthe amine group. The invention also relates to processes of mordantingand dye images utilizing such materials.

Various methods are known for mordanting acid dyes to Water-permeablecolloid layers in photographic elements. These methods utilize bothinorganic and organic compounds. In case of organic compounds, many ofthem which are useful in textile mordanting proce dures are not usefulin photographic emulsions because the compounds have a deleteriouseffect on the silver halide grains. Polymeric quaternary salts have beenproposed for the mordanting of acid dyes in the form of photographicimages, but they have the disadvantage of causing excessive fog andaffect the speed of the photographic emulsion. Polymeric quaternarysalts also markedly afifect the viscosity and consequently the coatingcharacteristics of the molten emulsion. Consequently, they can only besafely used in nonsensitive layers of photographic elements.

An object of this invention is to provide improvements in the art ofmordanting acid dyes in photographic Another object is to provide newphotographic film and paper elements wherein the silver halide emulsionlayers contain polymeric nitrogenous compounds which do not have adeleterious effect on the silver halide grains. A further object is to Astill further object is to provide such It has been discovered thatphotographic films and papers having a strong mordanting action on aciddyes can be made by incorporating in the. water-permeable 'silver halideemulsions thereof a polymeric polyamine having a main polymer chainconsisting solely of carbon atoms and containing a plurality of aminogroups .in Which the amino nitrogen has at least one hydrogen atom. Thepolymeric polyamines in question are selected from the class consistingof (a) polymeric polyamines in which the amino nitrogen, having at leastone hydrogen atom, is directly attached by a single bond to a carbonatom of the main polymer chain, and (b) polymeric polyamines containingprimary amino nitrogen atoms linked to a carbon atom of the main polymerchain through a methylene (-CHz-) group. Mixtures of two or more of thepolyamines can be used.

The polymeric polyamines described in the foregoing paragraph arecharacterized by having a main polymer chain consisting solely of carbonatoms and further char- 'ice acterized by having recurring substituentgroups of the formula:

I (CH RiNH wherein R1 is H or an alkyl radical of 1 to 12 carbon atoms,i. e., methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl,nonyl, decyl, undecyl and dodecyl; and x is the cardinal number of 0or 1. The compounds comprehended by this general formula have molecularWeights from 300 to 50,000.

The polymeric polyamines used in accordance with one aspect of thisinvention are obtained by the reductive amination of a monoolefin/carbonmonoxide polymer. These polymeric polyamines have a main polymer chainconsisting solely of carbon atoms and contain as lateral substituents aplurality of amino groups, Where R1 has the same meaning as above,attached directly to a carbon atom of the main polymer chain. Thesecompounds, when exemplified by those made by the reductive amination ofethylene/carbon monoxide polymers, have a plurality of units of thefollowing general formula:

RiNH (n Where n is an integer from 3 to 40 and R1 has the samesignificance as in Formula I. In the case of polymers made from otherolefins, they will have similar structures except that the -CHz-CH2- isreplaced by a radical or a CllHa on2oradical where propylene andisobutylene are used as the olefin.

In another important aspect of the invention, the polymeric polyaminesused in the silver halide dispersions are obtaine'dby the reduction of alinear polymer containing units selected from the group consisting ofacrylonitrile and alpha-methacrylonitrile units, said polymericpolyamineliaving a main polymer chain consisting solely of carbon atomswith the primary amino (-NH2) groups attached to the said main polymerchain through methylene (-CH2) groups which are lateral substituentsthereon. These compounds as exemplified by butadiene/acrylonitrile oralpha-methacrylonitrile copolymers are composed of a plurality of unitshaving the Formulae III and IV below:

wherein n is a positive integer of 1 to 10.

The polymeric polyamines described above that are useful in accordancewith the present invention may be made after the manner described inHoehn U. S. 2,495,255 patented January 20, 1950, and Pinkney U. S.2,585,583 patented February 12, 1952. The useful polymeric polyamines,however, may have a neutralization equivalent from 50 to 1,000 butpreferably have a neutral ization equivalent in the range from 150 to500. By neutralization equivalent is meant the weight of polyaminerequired to neutralize one equivalent weight of any strong acid.

The photographic elements, e. g., film or paper hearing at least onewater-permeable colloid silver halide emulsion containing one or more ofthe polymeric polyamines described above can be made in various manners.Thus the photographic films or paper can be made by any conventionalmethod and the polymeric polyarnine introduced into the photographicemulsion layer by impregnating it with an aqueous solution of thepolymeric polyamine. Since the additionsalts of the polymeric polyamineshave a markedly higher solubility than the free bases, the polyaminesare generally added in the form of the addition salt. This isconveniently done by dissolving the polymeric polyamine in aqueous acid,e. g., dilute aqueous acetic acid and impregnating the waterpermeablecolloid silver halide emulsion layer with the resulting solution.

Alternatively, the polymeric polyamines can be added to thewater-permeable colloid silver halide emulsion prior to coating, thatis, an emulsion which is made in the usual manner is admixed with anaqueous solution containing an addition salt, e. g., acetic acid salt ofthe polymeric amine.

The water-permeable colloids used in the emulsions may be any of theusual colloids used by photographic manufacturers. Thus the colloid maybe gelatin, agaragar, albumin, polyglycuronic acid, zein, collodion,polyvinyl alcohol, partially hydrolyzed polyvinyl acetate andinterpolymers thereof with unsaturated materials such as ethylene,styrene, maleic acid, etc. which have hydrophilic properties, polyvinylacetals, e. g., the acetal of polyvinyl alcohol with acetaldehyde orbenzaldehyde or water-soluble or hydrophilic cellulose derivatives.Suitable hydrophilic or water-permeable colloids of the above types aredescribed in U. S. Patents 2,110,491, 2,211,323, 2,276,322, 2,276,323,2,286,215 and 2,397,866.

The proportion of polymeric polyamine to waterpermeable colloid silverhalide emulsion may vary over a fairly wide range. Thus from 2.0 to100.0 grams of the mordant (the polymeric polyamine) in the form of theacid addition salt may be used for each 100 grams of gelatin or otherwater-permeable colloid used as the binding agent in the emulsion.

The invention will be further illustrated but is not intended to belimited by the following examples:

Example I A gelatino silver chloride emulsion of a kind suitable forpreparing a photographic printing paper of the contact type was made and3 one-liter portions were separated. To these 3 emulsions there wereadded, from a 2% aqueous acetic acid solution, 1.25, 2.5 and 5.0 gramsof the acetic acid addition salt of the polyamines obtained by thereductive amination of the polyketones prepared by the copolymerizationof ethylene and carbon monoxide in the ratios of 6 to 1, 6.9 to 1 and10.4 to 1,

respectively. These polyamines had molecular weights of 660, 1100 and1480 and neutralization equivalents of 574, 352 and 506, respectively.They were prepared after the manner described in Hoehn U. S. Patent No.2,495,255. The three aqueous emulsions were coated onto a baryta-coatedsheet of paper and dried. The resulting photographic papers were exposedto light and then fixed in a 24% aqueous solution of NazSzOaSHzO, washedand dried. The three papers were then treated in an acid dye solution ofthe following composition:

Grams Pontacyl Carmine 6B (Colour Index 57) 1.2 NaH2PO4l-I2O 15.0

H2O to make 1.0 liter.

and washed for 15 minutes. It was found that each of the photographicpapers were fastly dyed by the acid magenta dye. The photographicemulsion containing the polymeric amine having the neutralizationequivalent of 352 retained the greatest amount and that having theneutralization equivalent of 574 the least amount of dye.

Example H An aqueous gelatino silver chloride emulsion of the kind usedin making photographic printing papers of the contact type was preparedand divided into several portions. A polymeric polyamine obtained by thereduction of a butadiene/acrylonitrile copolymer of 4 to 1 mol ratio andhaving a neutralization equivalent of 378 was dissolved in 2% aqueousacetic acid to form the acetic acid addition salt. No added ingredientswere made to one control portion of the emulsion and chrome alum wasadded to a second portion. This solution was added in the quantitiesgiven in the following table to further respective portions of thesilver chloride 61111117 sion. These portions were then coated onto abarytacoated sheet of paper. The respective photographic papers wereexposed to a standard negative and then developed for one minute in asolution made of the following constituents:

Grams N-methyl-p-aminophenol sulfate 1.0 Sodium sulfite 15.0

Hydroquinone 4.0 Sodium carbonate (desiccated) 22.5 Potassium bromide0.63

Water to make 1.0 liter.

with the results given in the following table:

Print Speed (Seconds of Exposure) 3.5 Months Aging at Grams PolyamineAcetate Salt Per Liter of Em ls Room Fresh Temperature None 20 25 1.4219 20 2.84 17 18 6.65... 19 20 1.42 gm. chrome alum 25 36 The data givenin the above table show that the poly 5 and the dye densities (d2)determined, with: the results given in the following table:

It should be noted that while chrome alum is an effective mordant, ithas the disadvantage that it causes rapid hardening of the emulsion sothat often coating cannot be accomplished due to such hardening.

Example III A gelatino silver iodobromide emulsion of the positive typewas prepared for coating. It was divided into portions. To respectiveportions there were added 3.66 grams of the polyamines listed below per100 grams of gelatin. The resulting emulsions were coated onto acellulose triacetate film base bearing a thin gelatin anchor layer anddried. The resulting film elements were fixed in 24% aqueousNazSzOaSI-IzO solution, washed, dried and dipped into a magenta dyesolution of the type given in Example I for a period of ten minutes. Thefilms were cut in half and one half was quickly rinsed in water and theother half washed for a period of one hour. The two halves were driedand the dye densities determined as in Example H with the results givenin the following table:

I Percent De- Neutralization crease in Dye Polymeric Polyamine Mord-antEquivalent Density, 1-

Hour Washs (a) This polymeric utadiene/acrylonitrilc form of the aceticacid addition salt which was madeby dissolving the polyamine in 3%aqueous acetic acid.

polyamine was obtained by the reduction of a copolymer of 4 to 1 molratio and was used in the (b) This polymeric poiyamine was obtained bythe reduction of a butadienc/methaerylonitrilc copolymer of 4 to 1 mo]ratio and was used in the form of the acetic acid addition salt whichwas made by dissolving the polyamine in 3 aqueous acetic acid.

(0) This polymeric polyamine is the same type as (b) but has a 4.5 to 1mol ratio.

(d) This polymeric polyamine is the same as I being made from thereductive amination of oxide polymerization product. Each of thepolymeric polyamines, a, Z7 and c were made after the manner describedin U. S. Patent No. 2,585,583. The polymeric amide (d) was made afterthe manner described in U. S. Patent No. 2,495,255.

Photographic films of the type described in Example iii are useful inmaking cine color prints by imbibition dye transfer procedures. Thus, adry matrix film can be introduced into a dye bath containing anysuitable acid dye of the appropriate color and dyed. The dyed matrix isrinsed in water or dilute acetic acid and the excess blown oif. Apremordantcd film of the type described in Example Hi is soaked in waterat pH 7 for 10 seconds at 70 F. The dyed matrix is then contacted withthe premordanted film. The matrix and mordanted films are left inemulsion contact for a period of about one minute at 100 to 150 F. Thetwo films are then stripped apart and the matrix washed in water andeither dried for storage or redyed for a further imbibition printingprocess. Example IV A gelatino-;silver iodobromide emulsion of thepositive type was preparedfor coating. .It was divided into two thatdescribed in Example the ethylene/carbon men equal portions. No mordantwas added to one portion and to the other portion there was added 14.8gramsof the polymeric amine of butadiene/methacrylonitrile having aneutralization equivalent of 365 described under (b) of Example 111 pergrams of gelatin. The resulting emulsions were coated onto cellulosetriacetate bases bearing a thin anchoring layer and dried. The resultinglight-sensitive elements were exposed and proc essed as follows:

The element was developed for 3%. minutes in a devel-- oper of thefollowing composition:

Grams N-methyl-p-aminophenol sulfate 0.46 NazSOg 28.0

' Hydroquinone 3.4

Na2CO3H20 10.0 KBr 0.44?

Water to make 1.0 liter.

The element was then rinsed and fixed in the following composition:

a solution having Grams Sodium thiosulfate, Na2S2O3-5HzOt 240.0 Sodiumsulfite 10.0 Sodium bisulfite; 25.0

Water to make 1.0 liter.

in the same way. The resolution in terms of lines per millimeter of theresultant transferred dye image which is a measure of mordanting powerwas determined microscopically andfound to be as shown in the followingtable:

Resolution (lines/millimeter) Mordant (grams/100 grams of gelatin) iExample V An emulsion prepared as in Example III was divided into threeparts and 27 grams per hundred grams of gelatin of each of the acetate,and iodide salts of the polymeric amine-of butadiene/methacrylonitrilecopolymer (BB/MAN) described under (1;) of Example ilIwere added to twoof the divided parts respectively. The fifthi portion contained nomordanting agent." The samples:

were processed and tested as shown in Example IV except. that thesamples were also submitted to one hour washing as in Example Ill andthe following results were observed.

In place of the specific polymeric polyamines given in the foregoingexamples one may substitute other polymeric amines described intheforegoing patents having the requisite neutralization equivalent.Additional useful polyamines include isobutylene/ethylene/carbon monoxide polymeric amine, propylene/ethylene/carbon monoxe.

ide polymeric amine, isobutylene/ carbon monoxide polymeric amine,propylene/ carbon monoxide polymeric amine, and polyallylamine.

The mordanted films and papers of this invention are useful in varioustypes of dye printing or imbibition printing operations. Thus, they areuseful in the preparation of three color dye transfer prints on papersupports, in the preparation of monochrome dyed prints for specialeffects and for hand colored color prints.

The present invention is not limited to the use of a baryta-coated paperor a cellulose triacetate film base as the water-permeable silver halidelayers containing the polymeric polyamines can be deposited on varioussupports. Thus, the support may be composed of practically any type oftransparent film or any type of paper which is resistant to photographicprocessing solutions. Thus, the film may be composed of superpolymers,e. g., linear polyamides, cellulose nitrate, polyvinyl acetals,cellulose propionate, cellulose mixed esters, cellulose ethers, vinylchloride and copolymers, styrene, acrylonitrile and copolymers,polyesters, e. g., polyethylene terephthlates, vinyl acetate andcopolymers, vinyl fluoride and copolymers, polyvinyl alcohol;transparentized paper, etc. The coated film base of Alles et al.2,627,088 is especially useful.

The photographic films and papers of this invention have the advantagethat they have a strong mordanting action on acid dyes. A furtheradvantage resides in the fact that the polymeric polyamines cause littleor no fog in the resulting light-sensitive silver halide emulsionlayers. A still further advantage resides in the fact that the polymericpolyamines do not adversely affect the stability of the resultingemulsions. Thus, no significant loss of speed or fogging occurs uponaging of the film elements. Another advantage of the invention is thatthe mordants are easy to use and do not have a significant hardeningaction on the conventional types of water-permeable colloids. A furtheradvantage lies in the fact that polyamines have little or no effect onthe physical characteristics of molten photographic emulsions beforecoating.

What is claimed is:

l. A photographic element comprising a support hearing at least onewater-permeable colloid silver halide emulsion layer containing at leastone polymeric polyamine containing carbon, hydrogen and nitrogen atomsonly and having a main polymer chain consisting solely of carbon atoms,said polyamines being taken from the class consisting of polymericpolyamines in which the amino nitrogen atom has at least one hydrogenatom attached thereto and is directly attached by a single bond to acarbon atom of the main polymer chain and polymeric polyaminescontaining amino nitrogen atoms directly attached to a carbon atom ofthe main polymer chain through a single methylene group, said aminonitrogen atoms having at least one hydrogen atom attached thereto, saidpolyamine having a molecular Weight from 300 to 50,000 and aneutralization equivalent from 50 to 1,000.

2. A photographic element comprising a flexible sheet hearing at leastone water-permeable colloid silver halide emulsion layer containing apolymeric polyamine having a polymer chain consisting solely of carbonatoms in which the amino nitrogen atom has at least one hydrogen atomattached thereto and the nitrogen atom is directly attached by a singlebond to the carbon atom of the main polymer chain, said polyamine havinga molecular weight from 300 to 50,000 and a neutralization equivalentfrom 50 to 1,000.

3. An element as set forth in claim 2 wherein said sheet is abaryta-coated paper.

4. An element as set forth in claim 2 wherein said sheet is ahydrophobic film base.

5. A photographic element comprising a flexible sheet bearing at leastone water-permeable colloid silver halide emulsion layer containing apolymeric polyamine con sisting of carbon, hydrogen and nitrogen atomsonly and having a polymer chain consisting solely of carbon atomscontaining primary amino nitrogen atoms directly attached to a carbonatom of the main polymer chain through a single methylene group, saidpolyamine having a molecular weight from 300 to 50,000 and aneutralization equivalent from 50 to 1,000.

6. An element as set forth in claim 5 wherein said sheet is abaryta-coated paper.

7. An element as set forth in claim 5 wherein said sheet is ahydrophobic film base.

8. A photographic element comprising a flexible sheet bearing awater-permeable colloid silver halide emulsion layer containing apolymeric polyamine having a polymer chain consisting solely of carbonatoms having, as the sole units in the polymer chain, recurringintralinear units of the formula:

wherein n is a positive integer of 3 to 40 and R1 is a member taken fromthe group consisting of hydrogen and alkyl of 1 to 12 carbon atoms, saidpolyamines having a molecular weight from 300 to 50,000 and aneutralization equivalent from to 500.

9. A photographic element comprising a flexible sheet bearing awater-permeable colloid silver halide emulsion layer containing apolymeric polyamine having a polymer chain consisting solely of carbonatoms having, as the sole units in the polymer chain, recurringintralinear units of the formula:

wherein n is a positive integer of 1 to 10, said polyamines having amolecular weight from 300 to 50,000 and a new tralization equivalentfrom 150 to 500.

10. A photographic element comprising a flexible sheet bearing awater-permeable colloid silver halide emulsion layer containing apolymeric polyamine having a polymer chain consisting solely of carbonatoms having, as the sole units in the polymer chain, recurringintralinear units of the formula:

where n is an integer of 1 to 10 said polyamines having a molecularweight from 300 to 50,000 and a neutralization equivalent from 150 to500.

11. A photographic film comprising a flexible hydrophobic film basebearing at least one gelatin silver halide emulsion layer containing apolymeric polyamine having a polymer chain consisting solely of carbonatoms having, as the sole units in the polymer chains, recurringintralinear units of the formula:

wherein n is an integer of 3 to 40, said polyamines having a molecularweight from 300 to 50,000 and a neutralization equivalent from 150 to500.

12. A film element as set forth in claim 11 wherein said base iscomposed of a polyethylene terephthalate.

13. A photographic film comprising a flexible hydrophobic film basehearing at least one gelatin silver halide emulsion layer containing apolymeric polyamine having a polymer chain consisting solely of carbonatoms having,

as the sole units in the polymer chain, recurring intralinear units ofthe formula:

H -(UHz--CHzCHg-CH2)n-CH2-- CHr-NH: wherein n is a positive integer of 1to 10, said polyamines having a molecular weight from 300 to 50,000 anda neutralization equivalent from 150 to 500.

14. A film element as set forth in claim 12 wherein said film base iscomposed of polyethylene terephthalate.

15. A photographic film comprising a flexible hydrophobic film basebearing at least one gelatin silver halide emulsion layer containing apolymeric polyamine having a polymer chain consisting solely of carbonatoms having, as the sole units in the polymer chain, recurringintralinear units of the formula:

CH; (CH2-CH2-CH:CHa)n-CH:-( J- Ha-NH:

References Cited in the file of this patent UNITED STATES PATENTS2,423,460 McQueen July 8, 1947 2,486,191 Minsk et a1 Oct. 25, 1949FOREIGN PATENTS 648,472 Great Britain Ian. 3, 1951

